Reacción #2467980

Ecuación de reacción

Sulfuric acid

nitric acid

thiophene-2-carboxylic acid

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product

Rendimiento 75.0%

4-Nitrothiophene-2-carboxylic acid

Rendimiento 75.0%

Condiciones de reacción

Tratamiento posterior

1. 1
   workup.ADDITIONwas added to the above nitration mixture slowly for 15 min at the same temperature
2. 2
   workup.ADDITIONThe reaction mixture was poured into ice cold water
3. 3
   workup.STIRRINGstirred for 30 min
4. 4
   FiltraciónThe precipitated solid was filtered
5. 5
   Lavadowashed with cold water
6. 6
   Otrodried
7. 7
   ExtracciónThe filtrate was extracted with ethyl acetate
8. 8
   LavadoThe combined ethyl acetate layer was washed with water, brine
9. 9
   Secadodried over sodium sulfate
10. 10
    FiltraciónThe solution was filtered
11. 11
    Otroevaporated the solvent
12. 12
    workup.STIRRINGThe combined product was stirred with hexane (2×50 mL)
13. 13
    Filtraciónfiltered the solid
14. 14
    Otrodried

Procedimiento

Sulfuric acid (3.0 mL, 5.505 g, 56.17 mmol) was added to nitric acid (2.0 mL, 2.98 g, 49.6 mmol) slowly at 0-10° C. After completion of the addition, thiophene-2-carboxylic acid (2.8 g, 21.87 mmol) was added to the above nitration mixture slowly for 15 min at the same temperature and stirred the mixture for 1 h. The reaction mixture was poured into ice cold water and stirred for 30 min. The precipitated solid was filtered, washed with cold water and dried. The filtrate was extracted with ethyl acetate. The combined ethyl acetate layer was washed with water, brine and dried over sodium sulfate. The solution was filtered and evaporated the solvent. The combined product was stirred with hexane (2×50 mL) and filtered the solid and dried to give the product as an off-white solid (2.8 g, 75%), mp 110-118° C. The product was a mixture of two compounds by HPLC and 1H NMR and was proceeded to the next step.

Fuente